Update from @metpoliceuk
At this stage, the incident is being treated as a terrorist incident.
Following events at Westminster, City of London Police officers will be highly visible across the City. This is for reassurance purposes and there is no cause for concern.
Metropolitan Police says "a number of pedestrians" have been injured and officers remain at the scene after a car crashed into security barriers outside the Houses of Parliament. Not known if terror related at present
@SkyNewsBreak - Russian officials say at least 10 people have been injured in an explosion at a supermarket in Saint Petersburg's Kalininsky district and a criminal investigation has been launched